If it is not immoral to shoot dead an intruder into one's house without asking questions, why would it be immoral to shoot dead an intruder into one's country?

I presume that by "an intruder into one's country" you mean an illegal immigrant rather than, say, an invading enemy soldier. Otherwise, I'd answer differently. Does one own one's country in the way in which one owns one's house? I think not, or else I own much more real estate than I thought. Moreover, an intruder into one's house can plausibly be assumed to be a serious threat to oneself. I don't think this assumption is as plausible in the case of an illegal immigrant, all else being equal.

If someone were presented the option to permanently undo a major aspect of their own life, and "rewrite history", would it be morally wrong to do this? Consider the following scenario: a person dedicates their life to an ideal such as justice or peace or any morally sound ideal such as those. They sacrifice so much of their time, energy, life, and sanity to the fulfillment of this ideal. However, due to unforeseen circumstances their actions lead to an outcome they were unsatisfied with. Would it be wrong for this hypothetical person to change their entire life to avert this terrible fate?

Before I could consider the ethics of this scenario, I'd have to satisfy myself that it's a coherent scenario. Let's call the person in question "Jane." The scenario seems to require that something like the following be true: "Jane sacrificed much of her time and energy to achieve justice, but because her sacrificial actions led to an unsatisfying outcome Jane didn't sacrifice much of her time and energy to achieve justice." I can't see how such a scenario is comprehensible enough to be assessed ethically. The question also arises whether Jane's sacrificial actions contributed so much to Jane's identity -- to who she now is -- that it's incoherent to ask what Jane's life would be like now had she not made those sacrifices: we wouldn't be asking about Jane but about a numerically different person.

There seems to be a popular form of virtual atheism where the person says: I don't believe in god, but I don't accept that 'everything is permitted.' And then they grin in an idiotic way. If 'everything is permitted' means exactly the same thing as there are no laws but man made laws, what can they mean? All laws are arbitrary unless they where given by some power from above, or if the very universe is 'good.' What else can they mean? If it is some kind of conditioned response or Freudian figure (which leads to the belief in goodness and guilt), that is ultimately based on meaningless phylogenetic antecedents. So if someone says that don't they just mean they don't like to admit morals are meaningless or radically arbitrary? Perhaps because they are confused.

You seem to be arguing for this claim: Atheism implies that everything is morally permissible. In the view of many philosophers, myself included, that claim is false. These philosophers argue that objective truths about moral right and wrong not only needn't be God-made (or man-made) but couldn't be God-made (or man-made). I recommend reading Wes Morriston, "God and the Ontological Foundation of Morality," and Erik J. Wielenberg, "In Defense of Non-Natural, Non-Theistic Moral Realism" . On the issue of whether all laws require a lawgiver, please see my response to Question 5619 .

An acquaintance believes that mandatory vaccination laws are "immoral." Her basic argument, as best I understand it, is that even if vaccines benefit almost everyone, there IS a risk -- however small -- that someone may be injured or even killed by a vaccine. Therefore, to force someone to get a shot that might possibly be hurtful is immoral. Somehow she equates mandatory vaccination to slavery -- something being imposed on people against their will. I don't think mandatory vaccination laws are immoral in the least. Her argument seems pretty wrong to me. Is it?

If your acquaintance argues that mandatory vaccination is immoral because it exposes people, against their will, to the risk of injury or death, you might ask her if she thinks a mandatory seat belt law is also immoral, because on rare occasions seat belts cause injury or even death. Surely it matters how likely it is that people will be harmed by obeying the vaccination law or the seat belt law, compared to the likelihood that they'll be harmed by not getting vaccinated or not wearing a seat belt. In the case of seat belts, I take it that the latter risk is much higher. I presume the same holds for vaccination. There's another factor to consider: mandatory vaccination isn't just paternalistic intervention for the sake of those getting vaccinated. It also protects others from infection, including others who can't take the vaccine because they are (known to be) allergic to one of its ingredients. So even someone opposed in principle to paternalistic laws needs another argument against mandatory...

Is there any way to ultimately resolve, by reason or evidence, the conflict between moral relativism and moral realism? Reading about this issue makes me feel unsure about the real status of morality. Any suggestion would help.

If by "ultimately resolve by reason or evidence" you mean "offer reasons or evidence sufficient to get everyone to accept one side of the debate," then an ultimate resolution of any issue seems very unlikely, just as a matter of social psychology. If, instead, you mean "discover reasons or evidence sufficient to make up my own mind about this issue," then I hold out much more hope. I recommend starting with the SEP entries on moral realism , moral relativism , and moral anti-realism if you haven't yet read them. Each contains detailed discussion and lots of citations to further reading. When assessing criticisms of any view, it's of course essential to be as clear as possible about the content of the view being criticized and to make sure that the view being criticized is one that's actually held rather than a "straw man."

During a discussion in the pub the other day my friend suggested that morality -- and the associated concepts of right and wrong, good and bad -- doesn't objectively exist, and that the universe is therefore essentially indifferent and meaningless. Any meaning or idea of "rightness" or "wrongness" that we perceive is a completely subjective human construct. This seems to me to be intuitively incorrect, but is there a way to effectually counter this view?

Philosophers have been debating this issue for about 2500 years. As things now stand, most academic philosophers deny, or are inclined to deny, that moral rightness and wrongness are purely subjective: in the recent PhilPapers survey , a majority of "target faculty" favored moral realism over moral anti-realism. But it's an area of robust philosophical debate. You might start by looking at the SEP entries on moral realism and moral anti-realism . They contain careful discussions and lots of references to further reading.

Is murder illegal because its wrong? Or is murder wrong because its illegal?

Your first question -- Why is murder illegal? -- is a sociological and/or historical question about the law and therefore a question on which philosophers, as such, aren't experts. Nevertheless (!) I feel confident in saying that the answer is yes : the direction of explanation goes from moral wrongness to illegality. Murder is a form of homicide meeting various conditions, such as being intentional and being done "with malice aforethought." Why does modern society outlaw murder but not, say, an adult's listening to "Baby" by Justin Bieber? Both actions reflect badly on the agent, but only the former is regarded as a serious moral wrong. When they start making things illegal, liberal societies tend put actions meeting that description at the top of the list. Your second question is more properly philosophical, and I think the answer is clearly no . It's at least imaginable that a society's legal regime might outlaw some things but not outlaw murder. Yet murder would remain morally wrong:...

Religious people often claim that human rights must come from God. It seems to me that they could be wrong about their claim because of the objection posed by the Euthyphro dilemma. Am I right about this? Can we have a solid grounding of human rights even if there is no God?

For what it's worth, I'm confident that you're right: moral rights needn't come from God. On the issues raised by the Euthyphro dilemma, let me suggest that you start with the SEP entries linked here and here . As for human rights properly so-called, I'd urge you to question that concept for the reasons that I gestured at in my answers to Question 5602 and Question 5402 .

I have a question about atheism and semantics, although I'm not sure I can phrase it properly, as it also includes the concept of "belief" separate from "doctrine." Here goes: atheists claim that they do not believe in "God" while they do believe in ethics, morality, a concept of right and wrong. It seems to me that anyone who says they believe in right and wrong also implicitly believes that there is something more important than one's own personal ego gratification (in other words, everyone "should" curtail their own gratification to the extent that such gratification harms other people). To me, that seems semantically equivalent to a belief in God, except that the concept of "God" also includes an association in most people's minds with a particular doctrine. It sounds to me that atheists are merely rejecting all the doctrinal beliefs that accompany organized religion, while at the very root or core of the situation, do accept that they need to defer their own gratification to something greater or...

You asked, "How can a person say on one hand that they believe that something is more important than the self and also say at the same time that nothing exists that is more important than the self?" I agree that a person who said such a thing would be expressing a self-contradictory belief, a belief that therefore couldn't possibly be correct. However, I think it's simply a misuse of language to use the term "god" or "God" to refer to anything that someone regards as more important than gratifying his or her ego at that moment . If I resist the temptation to insult someone because I think it would be wrongfully hurtful, even if insulting him would gratify my ego, I don't thereby count as believing in God or gods. You dismissed "terminology and doctrine," as if they're irrelevant. But the meanings of words , such as "god" or "God," are of course entirely a matter of terminology, and in the case of religious terminology the meanings are often connected to one doctrine or another. By the same token...

How would a legal philosopher deal with the trolley problem compared to a moral philosopher? Would he come to a conclusion that is neither switch nor not switch? That is, either choice is equally legal?

You seem to be asking about the legality of switching or declining to switch, in which case your question is best answered by a lawyer rather than a philosopher of law. I'm not sure, but the answer may depend on the jurisdiction. It may also matter whether the person in a position to switch the trolley is legally authorized to be in that position or is, instead, a trespasser or intruder. I'm not suggesting that the answer provided by the law is totally irrelevant to the morally right answer. The law on this issue, if there is any, may reveal the moral attitude that we currently take toward it, which is relevant to some extent.